**4. Conclusions and Implications**

*4.1. Findings*

Results show that the model has high accuracy and can be combined with local policy to simulate the PLE space under future scenarios:


As a typical area with a backward economy and limited geographical conditions, Zhaotong city has unique characteristics of PLE space. Talking about the future development direction and whether the planning objectives can be achieved, the model constructed in this paper gives these answers:


#### *4.2. Contributions*

The study of the PLE space is important for the planning of regional sustainable development. Complicatedly, it involves geographical, ecological, and economic knowledge and experiments, requiring integrated research. This paper built an integrated optimization model by which PLE space can be simulated quantitatively and spatially, which enriches the current study of PLE. Additionally, it can be a powerful tool.

The SD model constructed takes local demographic and economic factors into account from a system science perspective. The mathematical relationships between the main factors are quantified by establishing equation and simulation parameters as a way to simulate the mechanism of urban operation. The FLUS model, based on the suitability probability using an ANN, is carried out in a roulette wheel way by considering the cost matrix, neighborhood influence, and other factors. For example, some constraints, as well as planning objectives, are embedded into the model in a parametric way, and the land allocation operations in the actual planning process are restored by different land class conversion rules.

In contrast to the multi-objective optimization model, which is often used to find the optimal solution [32], the coupled model in this paper can simulate the urban operation mechanism at a more microscopic scale and perform dynamic derivation in both time and space dimensions simultaneously with more flexible parameter adjustment. Moreover, this paper sets a variety of development scenarios in the form of parameters for the relevant indicators in local policies and assists in decision-making based on the simulation results. For Zhaotong city, economic development and environmental protection are advocated to be given equal importance. For other cities that also face urban development planning problems, the case study of this paper can provide inspiration.
